1. Field of the Invention
The present invention relates to a bearing manufacturing method for a compressor, and more particularly to a compressor bearing manufacturing method that is capable of improving a reliability of a compressor and improving an energy efficiency by increasing an abrasion resistance and reducing a friction coefficient.
2. Description of the Background Art
In general, as shown in FIG. 1, a compressor includes a casing 6 to which a suction tube 2 for sucking a coolant and a discharge tube 4 for discharging a compressed coolant are respectively connected, a drive unit 8 being disposed at a lower side of the casing 6 and generating a driving force, a rotational shaft 14 being rotated upon receipt of a rotational force generated by the drive unit 8, and a compressing unit 16 for being connected to an upper side of the rotational shaft 14 and compressing fluid upon receipt of the rotational force of the rotational shaft 14.
The drive unit 8 includes a stator 10 fixed in the circumferential direction of the casing 6 and a rotor 12 being disposed at certain distance at an inner circumferential surface of the stator 10, being rotated by an interaction with the stator 10, and being connected to the rotational shaft 14.
The compressing unit 16 includes a fixed scroll 28 having fixed wings 26 in an involute shape and fixed at an upper side of the casing 6, and a revolving scroll 32 having revolving wings 30 disposed at a certain distance from their respective fixed wings 26 to form a compressed space therebetween.
An upper frame 18 is installed at an upper portion of the casing 6 to support the upper portion of the rotational shaft 14 and supporting the compression unit 16, and a lower frame 20 is installed at a lower portion of the casing 6 to support the lower portion of the rotational shaft 14.
An upper bearing 22 is inserted between the upper frame 18 and the rotational shaft 14 to rotatably support the upper side of the rotational shaft 14, and a lower bearing 24 is inserted between the lower frame 20 and the rotational shaft 14 to rotatably support the lower side of the rotational shaft 14.
The upper and the lower bearings 22 and 24 should have an abrasion resistance so as to be used at a high load and at a high speed for a long period of time and should minimize an energy loss when the rotational shaft is rotatably moved.
The conventional bearing is a bearing which forms a copper lead powder sintered layer or a bearing of a type that a teflon is coated on an aluminum alloy material, copper lead powder sintered layer or aluminum alloy material.
However, the conventional compressor bearing manufactured as described above has the following problems.
That is, though it can satisfy the performance required for a compressor which uses a coolant of chlorofluorocarbon (CFC) group which is typically used as a coolant, if it uses a coolant of hydrofluorocarbon (HFC) group, an environment-friendly coolant, a greater abrasion resistance and less friction coefficient are required than the case where the chlorofluorocarbon (CFC) group coolant is used, resulting in that the compressor is not suitable to use the hydrate fluoride carbon (HFC).
In addition, in case that the bearing made by coating teflon on copper lead or an aluminum alloy is adopted to a compressor which uses the hydrofluorocarbon (HFC) group coolant, since the thickness of the teflon coated layer is hardly precisely manufactured, it is impossible to process for improving an inner diameter form of the bearing or the illumination of the surface of the bearing, resulting in that a gap is created between the bearing and the rotational shaft, which inevitably causes a vibration and noise. Then, the friction amount is relatively increased and the performance of the compressor is considerably degraded.
Therefore, an object of the present invention is to provide a bearing manufacturing method for a compressor that is capable of improving a reliability of a compressor and improving an energy efficiency by increasing an abrasion resistance and a friction coefficient for a compressor which uses a hydrofluorocarbon (HFC) is used as a coolant according to the tendency of using an environment-friendly coolant.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a bearing manufacturing method for a compressor including the steps of: molding an exterior of a bearing by using an aluminum (Al) material; forming an oxide-coated layer on the surface of the bearing member after the exterior of the bearing is completed; and electrolizing the bearing in tiomolybdenic acid ammonium solution and infiltrating a molybedene emulsion into the oxide-coated layer of the bearing.
In the bearing manufacturing method for a compressor of the present invention, in the second step of forming the oxide-coated film, electrolyte solution such as sulfuric acid (H2SO4) and oxalic acid is set as a cathode and a material to be coated is set as an anode, to which electric current is provided to generate an oxide-coated layer on the surface of the material.
In the bearing manufacturing method for a compressor of the present invention, in the third step, the bearing with the oxide-coated film formed is electrolized in 0.01xcx9c0.1 wt % pure tiomolybdenic ammonium aqueous solution and hydrogen ion discharged from a barrier layer of the oxide-coated layer and molybdenesulfide ion dissociated from the tiomolybdenic acid ammonium aqueous solution are interacted in each fine pores, so that molybedene emulsion can be deposited in the pores.
In the bearing manufacturing method for a compressor of the present invention, in the third step, the oxide-coated film has the thickness of 0.01xcx9c0.03 mm.
The bearing manufacturing method for a compressor of the present invention further includes abrading a bearing contact face to improve the illumination of the surface of the bearing after infiltrating the molybedene emulsion.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.